Rules for Using Apostrophes

Use apostrophes to form contractions (I'm, he's, they're).

Use apostrophes to take the place of missing letters in casual writing (Texas hold 'em).

Use apostrophes to take the place of missing numbers, such as when shortening a decade (the '60s). But when writing a decade, do not put an apostrophe between the final number and the "s.")

Use apostrophes to form possessives:

• For most singular nouns or names, add an apostrophe and an "s" to the end of the word (Bob's files, the librarian's wife).
• For plural nouns that don’t already end in "s," add an apostrophe and an "s" to the end of the word (the children's toys).
• For plural nouns or names that already end in "s," just add an apostrophe (the Goldbergs' house, the employees' benefits).
• Use an apostrophe only (without the "s") to form possessives for names that end in an "s" and have the "eez" sound (Achilles' heel).

You can sometimes use apostrophes to indicate relationships that aren’t possessive:

• Use an apostrophe in the plurals of letters or words if those terms would otherwise be confusing without it (straight A's).
• Use an apostrophe to indicate commonly accepted relationships between nouns (two weeks' notice, a doctor's appointment).